People are increasingly interacting with computers and other electronic devices in new and interesting ways. One such interaction approach involves making a detectable motion with respect to a device. While complex motion analysis devices are able to determine such motion with relative accuracy, this analysis is difficult to implement on consumer devices, particularly mobile or portable computing devices that generally have relatively simple camera elements. These camera elements often suffer from various limitations that make it difficult to determine relative position and motion from still or video image information. Such limitations also make it difficult to properly interpret motions of a user at a distance from a device for purposes of device input.